The present invention relates to a device and method for controlling insects. Many recently developed techniques used for the control of insects involve slow-release pesticide technology. The use of pest strips, collars, bands, and tags which have an insecticide contained throughout the substrate of the final device are described in U.S. Pat. No. 3,318,679; U.S. Pat. No. 3,944,662; U.S. Pat. No. 3,756,200; U.S. Pat. No. 3,942,480 and U.S. Pat. No. 4,195,075. The latter patent describes an insect control device containing an insecticidally-active isomer of .alpha.-cyano-3-phenoxy-benzyl-.alpha.-isopropyl-4-chlorophenylacetate. Application for U.S. Ser. No. 615,611, filed May 31, 1984, describes coated devices which enable the incorporation of insecticidal agents which were not suitable for incorporation into devices prepared by extrusion and injection molding.
The increased popularity of devices such as insecticidal animal ear tags over the past few years, has resulted in considerable effort to develop improved devices to overcome the problems which become apparent as their use increases. Improvements in design, compositions, and manufacturing techniques are constantly being sought to overcome problems such as breakage and loss, and to improve efficacy and ease of application. Breakage and loss occur in ear tags such as those described in U.S. Pat. No. 3,731,414, due to their size, design and method of attachment which results in portions of the tag being subjected to flex and stress in the field for prolonged periods of time. Additionally, breakage or weakness of a plastic tag can result from the incorporation of an active ingredient or mixture of active ingredients which may actually weaken the polymer matrix.
Interference of an active component with the polymerization or manufacturing process, resulting in weakness and breakage, is an area of great concern in the preparation of animal ear tags. An increasing emphasis is being placed on combinations of insecticidal ingredients, such as the pyrethroids with other insecticides, and the use of synergists, such as piperonyl butoxide, in order to increase the efficacy and spectrum of activity of insecticidal animal ear tags. Increases in the concentrations of active component is currently limited by the strength of the resulting plastic tag.
It is an object of this invention to provide compositions and devices which are not restricted by the above limitations.